Field of the Invention
The present invention relates to a technology for changing a representation form of a content displayed on a display.
Description of the Related Art
Information processing apparatus with multi-touchscreen display, such as tablet PCs (Personal Computer) and smart phones are gaining popularity. Such information processing apparatus is capable of changing the representation form of the content displayed on the touchscreen through gestures with one or more fingers. The representation form of the content is changed by, for example, scrolling (translating), zooming in, zooming out, rotating and the like. For example, when a finger touching the touchscreen is linearly moved in one direction, the content is accordingly scrolled to the direction. Further, when a distance between two fingers is decreased, the content is zoomed out for display. When a distance between two fingers is increased, the content is zoomed in for display.
Changing the content sometimes causes the content to go beyond a display area of the touchscreen. Also, changing the content sometimes causes the content to become reduced in size and the edge thereof is displayed on the touchscreen. Japanese Patent Application Laid-Open No. 2011-023004 discloses that, in a case where it is necessary to display an area beyond the edge of the content, margins are displayed in an area beyond the edge of the content. After the margins are displayed and the change of the content is completed, the content returns to a size within the range of the display area.
A predefined scaling factor is set for zoom-in ratio (or zoom-out ratio) to zoom in or zoom out the content. When the content is zoomed in (or zoomed out) beyond the predefined scaling factor, the content is temporarily zoomed in (or zoomed out) with the factor beyond the predetermined scaling factor for display. However, when the operation is terminated, the content returns to the size with the predefined scaling factor.
In Japanese Patent Application Laid-open No. 2011-023004, the content is temporarily zoomed in (or zoomed out) for display beyond the predefined scaling factor, which corresponds to a threshold for change of the content. Due to this, it is difficult for a user to learn the threshold for change in zooming in or zooming out the content, which sometimes causes the user to keep executing the zoom-in or zoom-out operation of the content even beyond the threshold for change. Similarly, when scrolling the content, the user sometimes keeps executing a scroll operation beyond the edge of the content.